Valve-gear



(No Model.)

P. W. JENKINS.

' VALVE GEAR.

No. 321,111. Patented June 30, 1885.

DZWEIESSES:

ATTORNEYS NITED STATES FRANK IV. JENKINS, OF BROOKLYN, NIHV YORK.

VALVE-GEAR.

.IFEGIFIUATION firming part of Letters Patent Ho. 321,111, dated June 30. 1885.

Application filed January 2. 1&5. (X0 model.)

To wZZ whom it may concern.-

Be ,it known that I, FRANK W. JnNKINs, of Brooklyn, county of Kings, and State of New York, have invented certain new and useful Improvements in Valve-Gear for Steam-Cylinders, of which the following is aspecification.

This invention has reference to an improved valve gear for the steamcylinders of directacting pumps, whereby the motion of the slidevalve is made entirely independent of the motion of the piston-rod; and the invention consists of the combination, with the steam-cylinder and its slide-valve, of a cam-shaft that actuates the slide-valve and an auxiliary steammotor that imparts rotary motion to said camshaft by an intermediate transmitting gearing.

In the accompanying drawings, Figure 1 represents a vertical longitudinal section on line as m, Fig. 2, of a steam-cylinder with my improved valve-gear. Fig. 2 is a plan, partly in horizontal section, of two steam-cylinders and duplex pump connected thereto; and Fig. 3 is a vertical transverse section of the same on line y y, Fig. 2.

Similar letters of reference indicate corresponding parts.

In the drawings, A represents a steam-cylinder; A, a direct-acting pump actuated by the piston of the steam-cylinder; B, the slidevalve, and O the valve-chest of the steam-cylinder. The steam-cylinder A is provided with the usual steam-inlet and exhaust-channels, and with steam-passages by which steam is supplied for cushioning the piston at each end of itsstroke. The slide-valve B is made of the usual construction, and provided with upwardly-extending transverse walls, I), that are engaged by a cam, d, of a shaft, D, which passes transversely through the slide chest, 0, and which turns in a stuffing-box, d, at one side of the same. The cam-shaft D is provided with a gear-wheel, e, which meshes with a pinion,e, of a crank-shaft, e, that turns in brackets e attached to the valvechest 0, its crank being connected with the piston of a small auxiliary steam cylinder, E, that turns in bearings of a second pair of brackets, f, of the main steam-cylinder A.

Steam is supplied through one of the hollow gudgeons of the auxiliary steam-cylinder A either by means of a valved pipe, 9, that comm'inicates with the steam-supply pipe G in front of the throttle-valve, as shown in the upper half of Fig. 2, or the steam may be supplied to the auxiliary steam-cylinder by a shorter valved connecting-pipe, g, from the steam-chest, as shown in the lower half of Fig. 2. The exhaust-steam passes off through the opposite hollow gudgeon of the auxiliary steam-cylinder E to the atmosphere. The pistoirrod of the steam-cylinder E is connected to the crank-shaft 6 By admitting steam to the auxiliary steamcylinder E an oscillating motion is imparted to the same by the action of its piston, which latter rotates the crank-shaft 6 that imparts,

by the pinion e and gear-wheel c, rotary motion to the cam-shaft D. The cam of the shaft D reciprocates the slide-valve B and actuates the same without any mechanical connection with the piston-rod or any other part of the steamengine.

In case of duplex pumps, two steam-cylinders are arranged parallel to each other, and the transmitting gear-wheels e 6 located intermediately between said cylinders, the slidevalves being actuated by separate cams placed upon the cam-shaft. If desired, the slidevalves of more than two engines may be operated by the same cam-shaft, which extends then transversely through the different steamchests.

The advantage of my improved independent valve-gear is that an absolutely positive motion is imparted to the slidevalve, which motion can be maintained Whether the main piston is in motion or at rest. When the auxiliary steam-motor which drives the slide-valves has been set in motion, steam may be admitted to the main cylinder, and by proper adjustment of the throttle-valves the speed of the piston or the number of strokesper minute may be made to correspond to the speed of the slide valve or valves. WVhen the engine is once running, either the speed of the valvedriving motor or of the main cylinder may be regulated by their respective throttle-valves, so that the speed of the motor can be adjusted to that of the main steam-cylinder, or vice versa.

By this independent valve-gear the motion of the main piston can be fully controlled and the same be made to make very short strokes in the middle of the cylinder, or it may go to the end and pause for such a length of time, according to the quick or slow reciprocating motion of the main slide-valve.

Having thus described myinvent-ion, I claim as new and desire to secure by Letters Patent 1. The combination, with a steam-cylinder and its slide-valve, of an independent auxiliary motor moving at greater speed than the slide -valve and intermediate transmitting mechanism by which motion is imparted to said slide-valve by the motor, substantially as set forth.

2. The combination, with the main steamcylinder, having separate steam supply and exhaust passages, and its slide-valve, of a transverse cam shaft actuating said slide valve, transmitting-gearing, and an auxiliary steam-motor that moves at greater speed than 

